This invention relates to weighing scales, and more particularly to weighing scales including digital data processing apparatus for computing and displaying a quantity representative of or proportional to the weight on the scale in accordance with a computational algorithm which is at least partly determined by variable parameters selected by the user of the scale.
Weighing scales in which the weight information is converted to digital signals which are processed digitally to produce a visual digital display are known. The digital data processing circuits employed in these scales typically make use of various digital parameters to at least partly control the computational algorithm of the scale. The functions performed by the scale can be varied by varying these parameters.
In many applications, it is desirable to allow the user of the scale to vary the function of the scale by selecting the appropriate values for these parameters. One way to accomplish this is to provide one or more selection switches on the scale to allow the user to select the desired parameter values. This adds to the number of controls which must be provided on the scale and may mean that basically the same scale must be provided in several different versions or models with different selection switches to meet the requirements of various users.
For example, some users of the scale may work with different measurement systems (e.g., ounces, grams, pennyweight, carats, grains, etc.) and may want to be able to select the weight units in which the scale computes and displays the weight of an object. Other users may wish to have the scale display monetary value rather than weight, with the ability to select an appropriate value per unit weight for use by the scale in converting weight to value. Still other users may work under conditions which may sometimes disturb the scale or with objects such as animals whose movements may sometimes disturb the scale. These users may wish to vary the sensitivity of the scale to such disturbances to adapt the scale to these various conditions.
If selection switches are provided on the scale for all of these various user needs, the construction and operation of the scale will be greatly complicated. On the other hand, if only those selection switches of interest to particular users are provided on each scale, a considerable number of different scale constructions may be required to satisfy the needs of all possible scale users.
It is therefore an object of this invention to improve and simplify weighing scales of the digital computational and display type.
It is a more particular object of this invention to provide an improved weighing scale of the digital computational and display type in which the computational parameters of the scale can be varied by the user without the use of any elaborate additional selection controls on the scale.